A thrombus migrating from the left femoral-popliteal deep vein through the right atrium leading to a massive pulmonary embolism

A 99-year-old male, without relevant past medical history presented to the emergency department for syncope. On arrival he was in shock with hypotension, tachycardia and cold extremities. 36% FIO2 were necessary to reach normal oxygen saturation. Arterial blood gas revealed a lactic acidosis with pH 7.1. Electrocardiogram showed sinus tachycardia and right bundle branch block. A focused cardiac ultrasound was performed revealing a voluminous and highly mobile thrombus in the right atrium moving through the tricuspid valve during diastole (Fig. 1, Suppl. Video 1). The right ventricle was dilated and presented systolic dysfunction with free wall hypokinesia. Anticoagulation by bolus of intravenous heparine and intravascular volume were administered immediately. Focused cardiac ultrasound was repeated a few minutes later due to clinical worsening. The thrombus was absent and the exam highlighted a more severely dilated and dysfunctional right ventricle with a systolodiastolic flattening of the interventricular septum, suggesting a massive pulmonary embolism due to thrombus migration. Intravenous thrombolysis with a half dose alteplase due to his advanced age was performed.

Figure 1.

First (upper panels) and second (lower panels) focused cardiac ultrasound. Upper panels: First focused cardiac ultrasound revealing the thrombus in the right atrium (white arrow) moving in the right ventricle through the tricuspid valve (right upper panel). Lower panels: Second focused cardiac ultrasound showing the absence of the thrombus with a clear systolodiastolic flattening of the interventricular septum (white arrow) in subcostal four-chamber view (left lower panel) and parasternal short-axis view (right lower panel).

The patient was admitted to intermediate care with a rapid resolution of shock and improvement of hypoxemia. An echo-Doppler of inferior limbs showed a left femoral-popliteal deep venous thrombosis, revealing the most likely origin of the thrombus. Pulmonary embolism was confirmed by computed tomography angiography, performed due to a worsening thoracic pain.

The patient celebrated his 100^th birthday in hospital and was transferred a few days later to a clinic for convalescence.

This case highlights the value of focused cardiac ultrasound for clinical decision making in hemodynamic unstable patients.